Search-engine giant Google Inc. has signed an agreement with the Grand River Dam Authority to buy electricity from a wind farm under construction in Canadian County.

Search engine giant Google Inc. has signed a deal for wind power from the Grand River Dam Authority to help power the Google data center in Pryor. Photos By Steve Gooch, The Oklahoman

Google will buy up to 48 megawatts of wind power from GRDA's interest in the Canadian Hills wind farm near El Reno. The 300-megawatt wind farm is expected to be complete by the end of the year and will be Oklahoma's largest wind farm with 135 turbines.

Google will use the electricity to operate its data center in Pryor in northeastern Oklahoma. The data center began operations in 2011.

“In conjunction with the electricity GRDA already supplies Google to operate its data center, Google will pay GRDA a premium to purchase renewable energy generated by Canadian Hills,” Gary Demasi, director of Google's global infrastructure team, said in a company blog post. “This brings the total amount of renewable energy for which Google has contracted to over 260 megawatts.”

Google last year signed a deal with NextEra Energy Resources to buy electricity directly from NextEra's Minco II Wind Energy Center in Grady and Caddo counties.

With the expansion of cloud computing, data centers have become large consumers of electricity. The Electric Power Research Institute estimates electricity use by data centers doubled from 2006 to 2011. Data centers now consume about 3 percent of the nation's electricity.

Google said it uses renewable energy for about 30 percent of its worldwide data center electricity. The company can't use renewable energy around the clock because data centers need to be operational 24 hours a day. GRDA approached Google in early 2012 about the possibility of adding wind power, officials said.